基于光学遥感的安达曼海内孤立波传播速度特性研究

The velocity characteristics of internal solitary waves in the Andaman Sea by optical remote sensing

安达曼海内孤立波非常活跃且错综复杂,传播速度是内孤立波的重要特征参量,本文采用光学遥感手段建立了内孤立波传播速度的计算方法。收集并处理大量Terra/Aqua-MODIS遥感图像,利用两景图像追踪同一内孤立波与同一激发源产生的内孤立波波群两种方法定量研究安达曼海内孤立波传播速度。研究结果表明:安达曼海内孤立波传播速度在0.5~2.7m/s之间,内孤立波传播方向主要受海底地形的影响,传播速度大小在传播过程中随水深变浅而呈减小的趋势,在深水区传播速度大小还呈现出季节性差异。

Internal solitary waves (ISWs) are widely distributed and have a large scale in the Andaman Sea. The velocity of ISWs is an important dynamic parameter. In this paper, approaches are proposed and demonstrated for calculating the propagation velocity of ISWs by optical remote sensing. The optical remote sensing data of MODIS in the Andaman Sea are collected and two methods are adopted to aquire velocity. One is to track the same ISWs based on two remote sensing satellites. The other is to find two or more packets of ISWs from the same generation in a single image. The overview of velocity distribution in the whole Andaman Sea is obtained by combining two methods. The results show that the propagation velocity of the Andaman Sea internal solitary wave ranges from 0.5 m/s to 2.7 m/s. The direction of the velocity is mainly influenced by the bottom topography, and the velocity decreases with the depth of water. In addition, different seasons correspond to different velocities in the deep water areas.